Conventional keyboards for computer systems are detachable units having generally horizontal, rectangular configurations. In addition to the QWERTY key layout, a typical keyboard includes a numeric keypad, dedicated and programmable function keys, and cursor control keys. An on-screen pointer control means, such as a remote mouse or a button or touch pad integrated with the keyboard, is also provided. Various accessories, including mouse pads and wrist rests, are typically positioned on the work surface proximate the keyboard.
It is well documented that the unnatural, palms-down typing position dictated by conventional keyboards results in user injuries. Prolonged use of conventional keyboards causes fatigue of the muscles, nerves and tendons of the forearms, wrists and hands, resulting in varying degrees of pain and numbness. Such injuries, if untreated, lead to Carpal Tunnel Syndrome and, for the employers of the injured employees, increased insurance premiums.
There is a documented relationship between keyboard-related injuries and traditional typing positions. First, users of conventional keyboards hold their wrists in a state of dorsal flection for prolonged periods of time without relief. (Dorsal flection of the wrist is the movement required when one's arm is extended forward and hand raised, palm outward, to signal"stop.") Such unnatural positioning of the wrist causes fatigue to the muscles, tendons and nerves. Second, keyboard users typically rest their wrists or the base of their hands on the hard desk surface or against a sharp comer of the desk while typing. Such positioning cuts off blood flow through the wrists to the hands and disrupts neurotransmission. Third, conventional keyboards require users to hold their wrists in a state of lateral planar extension for extended periods of time. That is, a user's hands, when properly positioned, are close together, bent at the wrists at approximately thirty degrees from the natural straight resting position, and splayed outward, pointing away from the user's body. Such unnatural positioning results in pain, numbness and fatigue to the hands, wrists and forearms.
While numerous mechanisms have been developed to compensate for the unnatural hand and wrist positioning mandated by existing keyboards, none have proven completely effective. For example, wrist rests lessen the degree of dorsal flection and cushion the wrists, but fail to address the problem of lateral planar extension."Wave" keyboards, i.e., keyboards having a wrist bridge incorporated therein with the keys arranged in v-shaped patterns rather than in straight lines, lessen the degree of dorsal flection and substantially eliminate lateral planar extension, but restrict normal blood flow and neurotransmission, as users' wrists are constantly pressed against the hard wrist bridge. Needs exist for keyboards that provide for hand and wrist positioning during data entry that does not restrict blood flow or lead to fatigue, pain and numbness in the forearms, wrists and hands.
Users of conventional keyboards assume generally upright postures when typing. Sitting upright for extended periods of time eventually causes fatigue to the spine and muscles and nerves of the lower back. To relieve that fatigue, users often slouch in their chairs, resulting in further stress to the back and neck. While innovative kneeling posture chairs or stools correct for the problem of back fatigue in some, but not all, cases, such chairs create additional stress on users' knees. Needs exist for keyboards that eliminate extended periods of stress on any single area of the human body by allowing users to frequently change posture without interrupting data entry.
A conventional keyboard measures about six inches by eighteen inches and occupies at least 118 square inches of desktop space. Additional desktop space must be allocated for a monitor, a mouse pad and a wrist rest. In all, it is customary for users to dedicate over three hundred square inches of desktop space to computer equipment. As many workstations offer limited work surfaces, users are forced to arrange the components in awkward and inconvenient positions, causing an increase in user discomfort and a decrease in productivity. Needs exist for keyboards that leave a small footprint on a desktop surface and that eliminate the need for additional space-consuming peripherals.
With conventional keyboards, operation of the mouse requires users to remove at least one hand from the keyboard. Once the mouse function is completed, users must then return their hands to the keyboard and reposition their fingers. That series of motions wastes time, creates mental confusion and leads to input errors, as the fingers are often repositioned on incorrect keys. Further, keyboard-integrated mouse mechanisms, such as touch pads, GLIDE POINTS.RTM. buttons and track balls, are difficult to control and are prone to accidental movement. Needs exist for keyboards that provide for the easy and efficient implementation of mouse functions without requiring users to remove their hands from typing positions along the surface of the keyboard.
Previous attempts to overcome the limitations of conventional keyboards have proven unsuccessful. For example, U.S. Pat. No. 5,426,449 discloses an ergonomic keyboard comprised of three angled sets of keys positioned to form a pyramid-shaped keyboard. Adjustable hand rests extend outward from the keyboard between the sets of keys for maintaining the hands and wrists of the user in relaxed arc positions. A track ball/mouse is provided on the front keypad, and the outwardly sloping and manually adjustable left and right keypads present the letter keys in the standard QWERTY format. While the device disclosed in U.S. Pat. No. 5,426,449 provides for the positioning of the user's hands in a more natural orientation, it does not relieve all strains in the wrists or prevent restriction of blood flow or neurotransmission through the hands or wrists, fails to readily accommodate changes in sitting posture, leaves a substantially large footprint on the desktop, and provides for difficult operation of the mouse, as users must either remove their hands from the keys or rely only on their thumbs for positioning the on-screen cursor.
U.S. Pat. Nos. 5,351,066 and 5,160,919 further disclose devices including input keys positioned for allowing users' hands to be placed in anatomically neutral positions. Those devices, however, fail to address many of the shortcomings of conventional keyboards discussed above.
It would be desirable therefore to provide a data input apparatus that maintains the hands in relaxed positions during data entry, automatically compensates for changes in sitting posture, occupies minimal desktop space, and is convenient and easy to use.